Macintosh-Tools/Retro68
1
0
Fork 0
mirror of https://github.com/autc04/Retro68.git synced 2024-12-03 10:49:58 +00:00
Code Issues Projects Releases Wiki Activity
7c526098af
Retro68/gcc/libgcc/config/avr/lib1funcs-fixed.S

1916 lines
41 KiB
ArmAsm
Raw Normal View History

upgrade to gcc 4.9.1
2014-09-21 17:33:12 +00:00
/* -*- Mode: Asm -*- */
;; Copyright (C) 2012-2014 Free Software Foundation, Inc.
;; Contributed by Sean D'Epagnier (sean@depagnier.com)
;; Georg-Johann Lay (avr@gjlay.de)
;; This file is free software; you can redistribute it and/or modify it
;; under the terms of the GNU General Public License as published by the
;; Free Software Foundation; either version 3, or (at your option) any
;; later version.
;; In addition to the permissions in the GNU General Public License, the
;; Free Software Foundation gives you unlimited permission to link the
;; compiled version of this file into combinations with other programs,
;; and to distribute those combinations without any restriction coming
;; from the use of this file. (The General Public License restrictions
;; do apply in other respects; for example, they cover modification of
;; the file, and distribution when not linked into a combine
;; executable.)
;; This file is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program; see the file COPYING. If not, write to
;; the Free Software Foundation, 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Fixed point library routines for AVR
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.section .text.libgcc.fixed, "ax", @progbits
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Conversions to float
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#if defined (L_fractqqsf)
DEFUN __fractqqsf
;; Move in place for SA -> SF conversion
clr r22
mov r23, r24
;; Sign-extend
lsl r24
sbc r24, r24
mov r25, r24
XJMP __fractsasf
ENDF __fractqqsf
#endif /* L_fractqqsf */
#if defined (L_fractuqqsf)
DEFUN __fractuqqsf
;; Move in place for USA -> SF conversion
clr r22
mov r23, r24
;; Zero-extend
clr r24
clr r25
XJMP __fractusasf
ENDF __fractuqqsf
#endif /* L_fractuqqsf */
#if defined (L_fracthqsf)
DEFUN __fracthqsf
;; Move in place for SA -> SF conversion
wmov 22, 24
;; Sign-extend
lsl r25
sbc r24, r24
mov r25, r24
XJMP __fractsasf
ENDF __fracthqsf
#endif /* L_fracthqsf */
#if defined (L_fractuhqsf)
DEFUN __fractuhqsf
;; Move in place for USA -> SF conversion
wmov 22, 24
;; Zero-extend
clr r24
clr r25
XJMP __fractusasf
ENDF __fractuhqsf
#endif /* L_fractuhqsf */
#if defined (L_fracthasf)
DEFUN __fracthasf
;; Move in place for SA -> SF conversion
clr r22
mov r23, r24
mov r24, r25
;; Sign-extend
lsl r25
sbc r25, r25
XJMP __fractsasf
ENDF __fracthasf
#endif /* L_fracthasf */
#if defined (L_fractuhasf)
DEFUN __fractuhasf
;; Move in place for USA -> SF conversion
clr r22
mov r23, r24
mov r24, r25
;; Zero-extend
clr r25
XJMP __fractusasf
ENDF __fractuhasf
#endif /* L_fractuhasf */
#if defined (L_fractsqsf)
DEFUN __fractsqsf
XCALL __floatsisf
;; Divide non-zero results by 2^31 to move the
;; decimal point into place
tst r25
breq 0f
subi r24, exp_lo (31)
sbci r25, exp_hi (31)
0: ret
ENDF __fractsqsf
#endif /* L_fractsqsf */
#if defined (L_fractusqsf)
DEFUN __fractusqsf
XCALL __floatunsisf
;; Divide non-zero results by 2^32 to move the
;; decimal point into place
cpse r25, __zero_reg__
subi r25, exp_hi (32)
ret
ENDF __fractusqsf
#endif /* L_fractusqsf */
#if defined (L_fractsasf)
DEFUN __fractsasf
XCALL __floatsisf
;; Divide non-zero results by 2^15 to move the
;; decimal point into place
tst r25
breq 0f
subi r24, exp_lo (15)
sbci r25, exp_hi (15)
0: ret
ENDF __fractsasf
#endif /* L_fractsasf */
#if defined (L_fractusasf)
DEFUN __fractusasf
XCALL __floatunsisf
;; Divide non-zero results by 2^16 to move the
;; decimal point into place
cpse r25, __zero_reg__
subi r25, exp_hi (16)
ret
ENDF __fractusasf
#endif /* L_fractusasf */
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Conversions from float
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#if defined (L_fractsfqq)
DEFUN __fractsfqq
;; Multiply with 2^{24+7} to get a QQ result in r25
subi r24, exp_lo (-31)
sbci r25, exp_hi (-31)
XCALL __fixsfsi
mov r24, r25
ret
ENDF __fractsfqq
#endif /* L_fractsfqq */
#if defined (L_fractsfuqq)
DEFUN __fractsfuqq
;; Multiply with 2^{24+8} to get a UQQ result in r25
subi r25, exp_hi (-32)
XCALL __fixunssfsi
mov r24, r25
ret
ENDF __fractsfuqq
#endif /* L_fractsfuqq */
#if defined (L_fractsfha)
DEFUN __fractsfha
;; Multiply with 2^{16+7} to get a HA result in r25:r24
subi r24, exp_lo (-23)
sbci r25, exp_hi (-23)
XJMP __fixsfsi
ENDF __fractsfha
#endif /* L_fractsfha */
#if defined (L_fractsfuha)
DEFUN __fractsfuha
;; Multiply with 2^24 to get a UHA result in r25:r24
subi r25, exp_hi (-24)
XJMP __fixunssfsi
ENDF __fractsfuha
#endif /* L_fractsfuha */
#if defined (L_fractsfhq)
FALIAS __fractsfsq
DEFUN __fractsfhq
;; Multiply with 2^{16+15} to get a HQ result in r25:r24
;; resp. with 2^31 to get a SQ result in r25:r22
subi r24, exp_lo (-31)
sbci r25, exp_hi (-31)
XJMP __fixsfsi
ENDF __fractsfhq
#endif /* L_fractsfhq */
#if defined (L_fractsfuhq)
FALIAS __fractsfusq
DEFUN __fractsfuhq
;; Multiply with 2^{16+16} to get a UHQ result in r25:r24
;; resp. with 2^32 to get a USQ result in r25:r22
subi r25, exp_hi (-32)
XJMP __fixunssfsi
ENDF __fractsfuhq
#endif /* L_fractsfuhq */
#if defined (L_fractsfsa)
DEFUN __fractsfsa
;; Multiply with 2^15 to get a SA result in r25:r22
subi r24, exp_lo (-15)
sbci r25, exp_hi (-15)
XJMP __fixsfsi
ENDF __fractsfsa
#endif /* L_fractsfsa */
#if defined (L_fractsfusa)
DEFUN __fractsfusa
;; Multiply with 2^16 to get a USA result in r25:r22
subi r25, exp_hi (-16)
XJMP __fixunssfsi
ENDF __fractsfusa
#endif /* L_fractsfusa */
;; For multiplication the functions here are called directly from
;; avr-fixed.md instead of using the standard libcall mechanisms.
;; This can make better code because GCC knows exactly which
;; of the call-used registers (not all of them) are clobbered. */
/*******************************************************
Fractional Multiplication 8 x 8 without MUL
*******************************************************/
#if defined (L_mulqq3) && !defined (__AVR_HAVE_MUL__)
;;; R23 = R24 * R25
;;; Clobbers: __tmp_reg__, R22, R24, R25
;;; Rounding: ???
DEFUN __mulqq3
XCALL __fmuls
;; TR 18037 requires that (-1) * (-1) does not overflow
;; The only input that can produce -1 is (-1)^2.
dec r23
brvs 0f
inc r23
0: ret
ENDF __mulqq3
#endif /* L_mulqq3 && ! HAVE_MUL */
/*******************************************************
Fractional Multiply .16 x .16 with and without MUL
*******************************************************/
#if defined (L_mulhq3)
;;; Same code with and without MUL, but the interfaces differ:
;;; no MUL: (R25:R24) = (R22:R23) * (R24:R25)
;;; Clobbers: ABI, called by optabs
;;; MUL: (R25:R24) = (R19:R18) * (R27:R26)
;;; Clobbers: __tmp_reg__, R22, R23
;;; Rounding: -0.5 LSB <= error <= 0.5 LSB
DEFUN __mulhq3
XCALL __mulhisi3
;; Shift result into place
lsl r23
rol r24
rol r25
brvs 1f
;; Round
sbrc r23, 7
adiw r24, 1
ret
1: ;; Overflow. TR 18037 requires (-1)^2 not to overflow
ldi r24, lo8 (0x7fff)
ldi r25, hi8 (0x7fff)
ret
ENDF __mulhq3
#endif /* defined (L_mulhq3) */
#if defined (L_muluhq3)
;;; Same code with and without MUL, but the interfaces differ:
;;; no MUL: (R25:R24) *= (R23:R22)
;;; Clobbers: ABI, called by optabs
;;; MUL: (R25:R24) = (R19:R18) * (R27:R26)
;;; Clobbers: __tmp_reg__, R22, R23
;;; Rounding: -0.5 LSB < error <= 0.5 LSB
DEFUN __muluhq3
XCALL __umulhisi3
;; Round
sbrc r23, 7
adiw r24, 1
ret
ENDF __muluhq3
#endif /* L_muluhq3 */
/*******************************************************
Fixed Multiply 8.8 x 8.8 with and without MUL
*******************************************************/
#if defined (L_mulha3)
;;; Same code with and without MUL, but the interfaces differ:
;;; no MUL: (R25:R24) = (R22:R23) * (R24:R25)
;;; Clobbers: ABI, called by optabs
;;; MUL: (R25:R24) = (R19:R18) * (R27:R26)
;;; Clobbers: __tmp_reg__, R22, R23
;;; Rounding: -0.5 LSB <= error <= 0.5 LSB
DEFUN __mulha3
XCALL __mulhisi3
lsl r22
rol r23
rol r24
XJMP __muluha3_round
ENDF __mulha3
#endif /* L_mulha3 */
#if defined (L_muluha3)
;;; Same code with and without MUL, but the interfaces differ:
;;; no MUL: (R25:R24) *= (R23:R22)
;;; Clobbers: ABI, called by optabs
;;; MUL: (R25:R24) = (R19:R18) * (R27:R26)
;;; Clobbers: __tmp_reg__, R22, R23
;;; Rounding: -0.5 LSB < error <= 0.5 LSB
DEFUN __muluha3
XCALL __umulhisi3
XJMP __muluha3_round
ENDF __muluha3
#endif /* L_muluha3 */
#if defined (L_muluha3_round)
DEFUN __muluha3_round
;; Shift result into place
mov r25, r24
mov r24, r23
;; Round
sbrc r22, 7
adiw r24, 1
ret
ENDF __muluha3_round
#endif /* L_muluha3_round */
/*******************************************************
Fixed Multiplication 16.16 x 16.16
*******************************************************/
;; Bits outside the result (below LSB), used in the signed version
#define GUARD __tmp_reg__
#if defined (__AVR_HAVE_MUL__)
;; Multiplier
#define A0 16
#define A1 A0+1
#define A2 A1+1
#define A3 A2+1
;; Multiplicand
#define B0 20
#define B1 B0+1
#define B2 B1+1
#define B3 B2+1
;; Result
#define C0 24
#define C1 C0+1
#define C2 C1+1
#define C3 C2+1
#if defined (L_mulusa3)
;;; (C3:C0) = (A3:A0) * (B3:B0)
DEFUN __mulusa3
set
;; Fallthru
ENDF __mulusa3
;;; Round for last digit iff T = 1
;;; Return guard bits in GUARD (__tmp_reg__).
;;; Rounding, T = 0: -1.0 LSB < error <= 0 LSB
;;; Rounding, T = 1: -0.5 LSB < error <= 0.5 LSB
DEFUN __mulusa3_round
;; Some of the MUL instructions have LSBs outside the result.
;; Don't ignore these LSBs in order to tame rounding error.
;; Use C2/C3 for these LSBs.
clr C0
clr C1
mul A0, B0 $ movw C2, r0
mul A1, B0 $ add C3, r0 $ adc C0, r1
mul A0, B1 $ add C3, r0 $ adc C0, r1 $ rol C1
;; Round if T = 1. Store guarding bits outside the result for rounding
;; and left-shift by the signed version (function below).
brtc 0f
sbrc C3, 7
adiw C0, 1
0: push C3
;; The following MULs don't have LSBs outside the result.
;; C2/C3 is the high part.
mul A0, B2 $ add C0, r0 $ adc C1, r1 $ sbc C2, C2
mul A1, B1 $ add C0, r0 $ adc C1, r1 $ sbci C2, 0
mul A2, B0 $ add C0, r0 $ adc C1, r1 $ sbci C2, 0
neg C2
mul A0, B3 $ add C1, r0 $ adc C2, r1 $ sbc C3, C3
mul A1, B2 $ add C1, r0 $ adc C2, r1 $ sbci C3, 0
mul A2, B1 $ add C1, r0 $ adc C2, r1 $ sbci C3, 0
mul A3, B0 $ add C1, r0 $ adc C2, r1 $ sbci C3, 0
neg C3
mul A1, B3 $ add C2, r0 $ adc C3, r1
mul A2, B2 $ add C2, r0 $ adc C3, r1
mul A3, B1 $ add C2, r0 $ adc C3, r1
mul A2, B3 $ add C3, r0
mul A3, B2 $ add C3, r0
;; Guard bits used in the signed version below.
pop GUARD
clr __zero_reg__
ret
ENDF __mulusa3_round
#endif /* L_mulusa3 */
#if defined (L_mulsa3)
;;; (C3:C0) = (A3:A0) * (B3:B0)
;;; Clobbers: __tmp_reg__, T
;;; Rounding: -0.5 LSB <= error <= 0.5 LSB
DEFUN __mulsa3
clt
XCALL __mulusa3_round
;; A posteriori sign extension of the operands
tst B3
brpl 1f
sub C2, A0
sbc C3, A1
1: sbrs A3, 7
rjmp 2f
sub C2, B0
sbc C3, B1
2:
;; Shift 1 bit left to adjust for 15 fractional bits
lsl GUARD
rol C0
rol C1
rol C2
rol C3
;; Round last digit
lsl GUARD
adc C0, __zero_reg__
adc C1, __zero_reg__
adc C2, __zero_reg__
adc C3, __zero_reg__
ret
ENDF __mulsa3
#endif /* L_mulsa3 */
#undef A0
#undef A1
#undef A2
#undef A3
#undef B0
#undef B1
#undef B2
#undef B3
#undef C0
#undef C1
#undef C2
#undef C3
#else /* __AVR_HAVE_MUL__ */
#define A0 18
#define A1 A0+1
#define A2 A0+2
#define A3 A0+3
#define B0 22
#define B1 B0+1
#define B2 B0+2
#define B3 B0+3
#define C0 22
#define C1 C0+1
#define C2 C0+2
#define C3 C0+3
;; __tmp_reg__
#define CC0 0
;; __zero_reg__
#define CC1 1
#define CC2 16
#define CC3 17
#define AA0 26
#define AA1 AA0+1
#define AA2 30
#define AA3 AA2+1
#if defined (L_mulsa3)
;;; (R25:R22) *= (R21:R18)
;;; Clobbers: ABI, called by optabs
;;; Rounding: -1 LSB <= error <= 1 LSB
DEFUN __mulsa3
push B0
push B1
push B3
clt
XCALL __mulusa3_round
pop r30
;; sign-extend B
bst r30, 7
brtc 1f
;; A1, A0 survived in R27:R26
sub C2, AA0
sbc C3, AA1
1:
pop AA1 ;; B1
pop AA0 ;; B0
;; sign-extend A. A3 survived in R31
bst AA3, 7
brtc 2f
sub C2, AA0
sbc C3, AA1
2:
;; Shift 1 bit left to adjust for 15 fractional bits
lsl GUARD
rol C0
rol C1
rol C2
rol C3
;; Round last digit
lsl GUARD
adc C0, __zero_reg__
adc C1, __zero_reg__
adc C2, __zero_reg__
adc C3, __zero_reg__
ret
ENDF __mulsa3
#endif /* L_mulsa3 */
#if defined (L_mulusa3)
;;; (R25:R22) *= (R21:R18)
;;; Clobbers: ABI, called by optabs
;;; Rounding: -1 LSB <= error <= 1 LSB
DEFUN __mulusa3
set
;; Fallthru
ENDF __mulusa3
;;; A[] survives in 26, 27, 30, 31
;;; Also used by __mulsa3 with T = 0
;;; Round if T = 1
;;; Return Guard bits in GUARD (__tmp_reg__), used by signed version.
DEFUN __mulusa3_round
push CC2
push CC3
; clear result
clr __tmp_reg__
wmov CC2, CC0
; save multiplicand
wmov AA0, A0
wmov AA2, A2
rjmp 3f
;; Loop the integral part
1: ;; CC += A * 2^n; n >= 0
add CC0,A0 $ adc CC1,A1 $ adc CC2,A2 $ adc CC3,A3
2: ;; A <<= 1
lsl A0 $ rol A1 $ rol A2 $ rol A3
3: ;; IBIT(B) >>= 1
;; Carry = n-th bit of B; n >= 0
lsr B3
ror B2
brcs 1b
sbci B3, 0
brne 2b
;; Loop the fractional part
;; B2/B3 is 0 now, use as guard bits for rounding
;; Restore multiplicand
wmov A0, AA0
wmov A2, AA2
rjmp 5f
4: ;; CC += A:Guard * 2^n; n < 0
add B3,B2 $ adc CC0,A0 $ adc CC1,A1 $ adc CC2,A2 $ adc CC3,A3
5:
;; A:Guard >>= 1
lsr A3 $ ror A2 $ ror A1 $ ror A0 $ ror B2
;; FBIT(B) <<= 1
;; Carry = n-th bit of B; n < 0
lsl B0
rol B1
brcs 4b
sbci B0, 0
brne 5b
;; Save guard bits and set carry for rounding
push B3
lsl B3
;; Move result into place
wmov C2, CC2
wmov C0, CC0
clr __zero_reg__
brtc 6f
;; Round iff T = 1
adc C0, __zero_reg__
adc C1, __zero_reg__
adc C2, __zero_reg__
adc C3, __zero_reg__
6:
pop GUARD
;; Epilogue
pop CC3
pop CC2
ret
ENDF __mulusa3_round
#endif /* L_mulusa3 */
#undef A0
#undef A1
#undef A2
#undef A3
#undef B0
#undef B1
#undef B2
#undef B3
#undef C0
#undef C1
#undef C2
#undef C3
#undef AA0
#undef AA1
#undef AA2
#undef AA3
#undef CC0
#undef CC1
#undef CC2
#undef CC3
#endif /* __AVR_HAVE_MUL__ */
#undef GUARD
/***********************************************************
Fixed unsigned saturated Multiplication 8.8 x 8.8
***********************************************************/
#define C0 22
#define C1 C0+1
#define C2 C0+2
#define C3 C0+3
#define SS __tmp_reg__
#if defined (L_usmuluha3)
DEFUN __usmuluha3
;; Widening multiply
#ifdef __AVR_HAVE_MUL__
;; Adjust interface
movw R26, R22
movw R18, R24
#endif /* HAVE MUL */
XCALL __umulhisi3
tst C3
brne .Lmax
;; Round, target is in C1..C2
lsl C0
adc C1, __zero_reg__
adc C2, __zero_reg__
brcs .Lmax
;; Move result into place
mov C3, C2
mov C2, C1
ret
.Lmax:
;; Saturate
ldi C2, 0xff
ldi C3, 0xff
ret
ENDF __usmuluha3
#endif /* L_usmuluha3 */
/***********************************************************
Fixed signed saturated Multiplication s8.7 x s8.7
***********************************************************/
#if defined (L_ssmulha3)
DEFUN __ssmulha3
;; Widening multiply
#ifdef __AVR_HAVE_MUL__
;; Adjust interface
movw R26, R22
movw R18, R24
#endif /* HAVE MUL */
XCALL __mulhisi3
;; Adjust decimal point
lsl C0
rol C1
rol C2
brvs .LsatC3.3
;; The 9 MSBs must be the same
rol C3
sbc SS, SS
cp C3, SS
brne .LsatSS
;; Round
lsl C0
adc C1, __zero_reg__
adc C2, __zero_reg__
brvs .Lmax
;; Move result into place
mov C3, C2
mov C2, C1
ret
.Lmax:
;; Load 0x7fff
clr C3
.LsatC3.3:
;; C3 < 0 --> 0x8000
;; C3 >= 0 --> 0x7fff
mov SS, C3
.LsatSS:
;; Load min / max value:
;; SS = -1 --> 0x8000
;; SS = 0 --> 0x7fff
ldi C3, 0x7f
ldi C2, 0xff
sbrc SS, 7
adiw C2, 1
ret
ENDF __ssmulha3
#endif /* L_ssmulha3 */
#undef C0
#undef C1
#undef C2
#undef C3
#undef SS
/***********************************************************
Fixed unsigned saturated Multiplication 16.16 x 16.16
***********************************************************/
#define C0 18
#define C1 C0+1
#define C2 C0+2
#define C3 C0+3
#define C4 C0+4
#define C5 C0+5
#define C6 C0+6
#define C7 C0+7
#define SS __tmp_reg__
#if defined (L_usmulusa3)
;; R22[4] = R22[4] *{ssat} R18[4]
;; Ordinary ABI function
DEFUN __usmulusa3
;; Widening multiply
XCALL __umulsidi3
or C7, C6
brne .Lmax
;; Round, target is in C2..C5
lsl C1
adc C2, __zero_reg__
adc C3, __zero_reg__
adc C4, __zero_reg__
adc C5, __zero_reg__
brcs .Lmax
;; Move result into place
wmov C6, C4
wmov C4, C2
ret
.Lmax:
;; Saturate
ldi C7, 0xff
ldi C6, 0xff
wmov C4, C6
ret
ENDF __usmulusa3
#endif /* L_usmulusa3 */
/***********************************************************
Fixed signed saturated Multiplication s16.15 x s16.15
***********************************************************/
#if defined (L_ssmulsa3)
;; R22[4] = R22[4] *{ssat} R18[4]
;; Ordinary ABI function
DEFUN __ssmulsa3
;; Widening multiply
XCALL __mulsidi3
;; Adjust decimal point
lsl C1
rol C2
rol C3
rol C4
rol C5
brvs .LsatC7.7
;; The 17 MSBs must be the same
rol C6
rol C7
sbc SS, SS
cp C6, SS
cpc C7, SS
brne .LsatSS
;; Round
lsl C1
adc C2, __zero_reg__
adc C3, __zero_reg__
adc C4, __zero_reg__
adc C5, __zero_reg__
brvs .Lmax
;; Move result into place
wmov C6, C4
wmov C4, C2
ret
.Lmax:
;; Load 0x7fffffff
clr C7
.LsatC7.7:
;; C7 < 0 --> 0x80000000
;; C7 >= 0 --> 0x7fffffff
lsl C7
sbc SS, SS
.LsatSS:
;; Load min / max value:
;; SS = -1 --> 0x80000000
;; SS = 0 --> 0x7fffffff
com SS
mov C4, SS
mov C5, C4
wmov C6, C4
subi C7, 0x80
ret
ENDF __ssmulsa3
#endif /* L_ssmulsa3 */
#undef C0
#undef C1
#undef C2
#undef C3
#undef C4
#undef C5
#undef C6
#undef C7
#undef SS
/*******************************************************
Fractional Division 8 / 8
*******************************************************/
#define r_divd r25 /* dividend */
#define r_quo r24 /* quotient */
#define r_div r22 /* divisor */
#define r_sign __tmp_reg__
#if defined (L_divqq3)
DEFUN __divqq3
mov r_sign, r_divd
eor r_sign, r_div
sbrc r_div, 7
neg r_div
sbrc r_divd, 7
neg r_divd
XCALL __divqq_helper
lsr r_quo
sbrc r_sign, 7 ; negate result if needed
neg r_quo
ret
ENDF __divqq3
#endif /* L_divqq3 */
#if defined (L_udivuqq3)
DEFUN __udivuqq3
cp r_divd, r_div
brsh 0f
XJMP __divqq_helper
;; Result is out of [0, 1) ==> Return 1 - eps.
0: ldi r_quo, 0xff
ret
ENDF __udivuqq3
#endif /* L_udivuqq3 */
#if defined (L_divqq_helper)
DEFUN __divqq_helper
clr r_quo ; clear quotient
inc __zero_reg__ ; init loop counter, used per shift
__udivuqq3_loop:
lsl r_divd ; shift dividend
brcs 0f ; dividend overflow
cp r_divd,r_div ; compare dividend & divisor
brcc 0f ; dividend >= divisor
rol r_quo ; shift quotient (with CARRY)
rjmp __udivuqq3_cont
0:
sub r_divd,r_div ; restore dividend
lsl r_quo ; shift quotient (without CARRY)
__udivuqq3_cont:
lsl __zero_reg__ ; shift loop-counter bit
brne __udivuqq3_loop
com r_quo ; complement result
; because C flag was complemented in loop
ret
ENDF __divqq_helper
#endif /* L_divqq_helper */
#undef r_divd
#undef r_quo
#undef r_div
#undef r_sign
/*******************************************************
Fractional Division 16 / 16
*******************************************************/
#define r_divdL 26 /* dividend Low */
#define r_divdH 27 /* dividend Hig */
#define r_quoL 24 /* quotient Low */
#define r_quoH 25 /* quotient High */
#define r_divL 22 /* divisor */
#define r_divH 23 /* divisor */
#define r_cnt 21
#if defined (L_divhq3)
DEFUN __divhq3
mov r0, r_divdH
eor r0, r_divH
sbrs r_divH, 7
rjmp 1f
NEG2 r_divL
1:
sbrs r_divdH, 7
rjmp 2f
NEG2 r_divdL
2:
cp r_divdL, r_divL
cpc r_divdH, r_divH
breq __divhq3_minus1 ; if equal return -1
XCALL __udivuhq3
lsr r_quoH
ror r_quoL
brpl 9f
;; negate result if needed
NEG2 r_quoL
9:
ret
__divhq3_minus1:
ldi r_quoH, 0x80
clr r_quoL
ret
ENDF __divhq3
#endif /* defined (L_divhq3) */
#if defined (L_udivuhq3)
DEFUN __udivuhq3
sub r_quoH,r_quoH ; clear quotient and carry
;; FALLTHRU
ENDF __udivuhq3
DEFUN __udivuha3_common
clr r_quoL ; clear quotient
ldi r_cnt,16 ; init loop counter
__udivuhq3_loop:
rol r_divdL ; shift dividend (with CARRY)
rol r_divdH
brcs __udivuhq3_ep ; dividend overflow
cp r_divdL,r_divL ; compare dividend & divisor
cpc r_divdH,r_divH
brcc __udivuhq3_ep ; dividend >= divisor
rol r_quoL ; shift quotient (with CARRY)
rjmp __udivuhq3_cont
__udivuhq3_ep:
sub r_divdL,r_divL ; restore dividend
sbc r_divdH,r_divH
lsl r_quoL ; shift quotient (without CARRY)
__udivuhq3_cont:
rol r_quoH ; shift quotient
dec r_cnt ; decrement loop counter
brne __udivuhq3_loop
com r_quoL ; complement result
com r_quoH ; because C flag was complemented in loop
ret
ENDF __udivuha3_common
#endif /* defined (L_udivuhq3) */
/*******************************************************
Fixed Division 8.8 / 8.8
*******************************************************/
#if defined (L_divha3)
DEFUN __divha3
mov r0, r_divdH
eor r0, r_divH
sbrs r_divH, 7
rjmp 1f
NEG2 r_divL
1:
sbrs r_divdH, 7
rjmp 2f
NEG2 r_divdL
2:
XCALL __udivuha3
lsr r_quoH ; adjust to 7 fractional bits
ror r_quoL
sbrs r0, 7 ; negate result if needed
ret
NEG2 r_quoL
ret
ENDF __divha3
#endif /* defined (L_divha3) */
#if defined (L_udivuha3)
DEFUN __udivuha3
mov r_quoH, r_divdL
mov r_divdL, r_divdH
clr r_divdH
lsl r_quoH ; shift quotient into carry
XJMP __udivuha3_common ; same as fractional after rearrange
ENDF __udivuha3
#endif /* defined (L_udivuha3) */
#undef r_divdL
#undef r_divdH
#undef r_quoL
#undef r_quoH
#undef r_divL
#undef r_divH
#undef r_cnt
/*******************************************************
Fixed Division 16.16 / 16.16
*******************************************************/
#define r_arg1L 24 /* arg1 gets passed already in place */
#define r_arg1H 25
#define r_arg1HL 26
#define r_arg1HH 27
#define r_divdL 26 /* dividend Low */
#define r_divdH 27
#define r_divdHL 30
#define r_divdHH 31 /* dividend High */
#define r_quoL 22 /* quotient Low */
#define r_quoH 23
#define r_quoHL 24
#define r_quoHH 25 /* quotient High */
#define r_divL 18 /* divisor Low */
#define r_divH 19
#define r_divHL 20
#define r_divHH 21 /* divisor High */
#define r_cnt __zero_reg__ /* loop count (0 after the loop!) */
#if defined (L_divsa3)
DEFUN __divsa3
mov r0, r_arg1HH
eor r0, r_divHH
sbrs r_divHH, 7
rjmp 1f
NEG4 r_divL
1:
sbrs r_arg1HH, 7
rjmp 2f
NEG4 r_arg1L
2:
XCALL __udivusa3
lsr r_quoHH ; adjust to 15 fractional bits
ror r_quoHL
ror r_quoH
ror r_quoL
sbrs r0, 7 ; negate result if needed
ret
;; negate r_quoL
XJMP __negsi2
ENDF __divsa3
#endif /* defined (L_divsa3) */
#if defined (L_udivusa3)
DEFUN __udivusa3
ldi r_divdHL, 32 ; init loop counter
mov r_cnt, r_divdHL
clr r_divdHL
clr r_divdHH
wmov r_quoL, r_divdHL
lsl r_quoHL ; shift quotient into carry
rol r_quoHH
__udivusa3_loop:
rol r_divdL ; shift dividend (with CARRY)
rol r_divdH
rol r_divdHL
rol r_divdHH
brcs __udivusa3_ep ; dividend overflow
cp r_divdL,r_divL ; compare dividend & divisor
cpc r_divdH,r_divH
cpc r_divdHL,r_divHL
cpc r_divdHH,r_divHH
brcc __udivusa3_ep ; dividend >= divisor
rol r_quoL ; shift quotient (with CARRY)
rjmp __udivusa3_cont
__udivusa3_ep:
sub r_divdL,r_divL ; restore dividend
sbc r_divdH,r_divH
sbc r_divdHL,r_divHL
sbc r_divdHH,r_divHH
lsl r_quoL ; shift quotient (without CARRY)
__udivusa3_cont:
rol r_quoH ; shift quotient
rol r_quoHL
rol r_quoHH
dec r_cnt ; decrement loop counter
brne __udivusa3_loop
com r_quoL ; complement result
com r_quoH ; because C flag was complemented in loop
com r_quoHL
com r_quoHH
ret
ENDF __udivusa3
#endif /* defined (L_udivusa3) */
#undef r_arg1L
#undef r_arg1H
#undef r_arg1HL
#undef r_arg1HH
#undef r_divdL
#undef r_divdH
#undef r_divdHL
#undef r_divdHH
#undef r_quoL
#undef r_quoH
#undef r_quoHL
#undef r_quoHH
#undef r_divL
#undef r_divH
#undef r_divHL
#undef r_divHH
#undef r_cnt
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Saturation, 1 Byte
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; First Argument and Return Register
#define A0 24
#if defined (L_ssabs_1)
DEFUN __ssabs_1
sbrs A0, 7
ret
neg A0
sbrc A0,7
dec A0
ret
ENDF __ssabs_1
#endif /* L_ssabs_1 */
#undef A0
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Saturation, 2 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; First Argument and Return Register
#define A0 24
#define A1 A0+1
#if defined (L_ssneg_2)
DEFUN __ssneg_2
NEG2 A0
brvc 0f
sbiw A0, 1
0: ret
ENDF __ssneg_2
#endif /* L_ssneg_2 */
#if defined (L_ssabs_2)
DEFUN __ssabs_2
sbrs A1, 7
ret
XJMP __ssneg_2
ENDF __ssabs_2
#endif /* L_ssabs_2 */
#undef A0
#undef A1
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Saturation, 4 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; First Argument and Return Register
#define A0 22
#define A1 A0+1
#define A2 A0+2
#define A3 A0+3
#if defined (L_ssneg_4)
DEFUN __ssneg_4
XCALL __negsi2
brvc 0f
ldi A3, 0x7f
ldi A2, 0xff
ldi A1, 0xff
ldi A0, 0xff
0: ret
ENDF __ssneg_4
#endif /* L_ssneg_4 */
#if defined (L_ssabs_4)
DEFUN __ssabs_4
sbrs A3, 7
ret
XJMP __ssneg_4
ENDF __ssabs_4
#endif /* L_ssabs_4 */
#undef A0
#undef A1
#undef A2
#undef A3
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Saturation, 8 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; First Argument and Return Register
#define A0 18
#define A1 A0+1
#define A2 A0+2
#define A3 A0+3
#define A4 A0+4
#define A5 A0+5
#define A6 A0+6
#define A7 A0+7
#if defined (L_clr_8)
FALIAS __usneguta2
FALIAS __usneguda2
FALIAS __usnegudq2
;; Clear Carry and all Bytes
DEFUN __clr_8
;; Clear Carry and set Z
sub A7, A7
;; FALLTHRU
ENDF __clr_8
;; Propagate Carry to all Bytes, Carry unaltered
DEFUN __sbc_8
sbc A7, A7
sbc A6, A6
wmov A4, A6
wmov A2, A6
wmov A0, A6
ret
ENDF __sbc_8
#endif /* L_clr_8 */
#if defined (L_ssneg_8)
FALIAS __ssnegta2
FALIAS __ssnegda2
FALIAS __ssnegdq2
DEFUN __ssneg_8
XCALL __negdi2
brvc 0f
;; A[] = 0x7fffffff
sec
XCALL __sbc_8
ldi A7, 0x7f
0: ret
ENDF __ssneg_8
#endif /* L_ssneg_8 */
#if defined (L_ssabs_8)
FALIAS __ssabsta2
FALIAS __ssabsda2
FALIAS __ssabsdq2
DEFUN __ssabs_8
sbrs A7, 7
ret
XJMP __ssneg_8
ENDF __ssabs_8
#endif /* L_ssabs_8 */
;; Second Argument
#define B0 10
#define B1 B0+1
#define B2 B0+2
#define B3 B0+3
#define B4 B0+4
#define B5 B0+5
#define B6 B0+6
#define B7 B0+7
#if defined (L_usadd_8)
FALIAS __usadduta3
FALIAS __usadduda3
FALIAS __usaddudq3
DEFUN __usadd_8
XCALL __adddi3
brcs 0f
ret
0: ;; A[] = 0xffffffff
XJMP __sbc_8
ENDF __usadd_8
#endif /* L_usadd_8 */
#if defined (L_ussub_8)
FALIAS __ussubuta3
FALIAS __ussubuda3
FALIAS __ussubudq3
DEFUN __ussub_8
XCALL __subdi3
brcs 0f
ret
0: ;; A[] = 0
XJMP __clr_8
ENDF __ussub_8
#endif /* L_ussub_8 */
#if defined (L_ssadd_8)
FALIAS __ssaddta3
FALIAS __ssaddda3
FALIAS __ssadddq3
DEFUN __ssadd_8
XCALL __adddi3
brvc 0f
;; A = (B >= 0) ? INT64_MAX : INT64_MIN
cpi B7, 0x80
XCALL __sbc_8
subi A7, 0x80
0: ret
ENDF __ssadd_8
#endif /* L_ssadd_8 */
#if defined (L_sssub_8)
FALIAS __sssubta3
FALIAS __sssubda3
FALIAS __sssubdq3
DEFUN __sssub_8
XCALL __subdi3
brvc 0f
;; A = (B < 0) ? INT64_MAX : INT64_MIN
ldi A7, 0x7f
cp A7, B7
XCALL __sbc_8
subi A7, 0x80
0: ret
ENDF __sssub_8
#endif /* L_sssub_8 */
#undef A0
#undef A1
#undef A2
#undef A3
#undef A4
#undef A5
#undef A6
#undef A7
#undef B0
#undef B1
#undef B2
#undef B3
#undef B4
#undef B5
#undef B6
#undef B7
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rounding Helpers
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#ifdef L_mask1
#define AA 24
#define CC 25
;; R25 = 1 << (R24 & 7)
;; CC = 1 << (AA & 7)
;; Clobbers: None
DEFUN __mask1
;; CC = 2 ^ AA.1
ldi CC, 1 << 2
sbrs AA, 1
ldi CC, 1 << 0
;; CC *= 2 ^ AA.0
sbrc AA, 0
lsl CC
;; CC *= 2 ^ AA.2
sbrc AA, 2
swap CC
ret
ENDF __mask1
#undef AA
#undef CC
#endif /* L_mask1 */
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The rounding point. Any bits smaller than
;; 2^{-RP} will be cleared.
#define RP R24
#define A0 22
#define A1 A0 + 1
#define C0 24
#define C1 C0 + 1
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rounding, 1 Byte
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#ifdef L_roundqq3
;; R24 = round (R22, R24)
;; Clobbers: R22, __tmp_reg__
DEFUN __roundqq3
mov __tmp_reg__, C1
subi RP, __QQ_FBIT__ - 1
neg RP
;; R25 = 1 << RP (Total offset is FBIT-1 - RP)
XCALL __mask1
mov C0, C1
;; Add-Saturate 2^{-RP-1}
add A0, C0
brvc 0f
ldi C0, 0x7f
rjmp 9f
0: ;; Mask out bits beyond RP
lsl C0
neg C0
and C0, A0
9: mov C1, __tmp_reg__
ret
ENDF __roundqq3
#endif /* L_roundqq3 */
#ifdef L_rounduqq3
;; R24 = round (R22, R24)
;; Clobbers: R22, __tmp_reg__
DEFUN __rounduqq3
mov __tmp_reg__, C1
subi RP, __UQQ_FBIT__ - 1
neg RP
;; R25 = 1 << RP (Total offset is FBIT-1 - RP)
XCALL __mask1
mov C0, C1
;; Add-Saturate 2^{-RP-1}
add A0, C0
brcc 0f
ldi C0, 0xff
rjmp 9f
0: ;; Mask out bits beyond RP
lsl C0
neg C0
and C0, A0
9: mov C1, __tmp_reg__
ret
ENDF __rounduqq3
#endif /* L_rounduqq3 */
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rounding, 2 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#ifdef L_addmask_2
;; [ R25:R24 = 1 << (R24 & 15)
;; R23:R22 += 1 << (R24 & 15) ]
;; SREG is set according to the addition
DEFUN __addmask_2
;; R25 = 1 << (R24 & 7)
XCALL __mask1
cpi RP, 1 << 3
sbc C0, C0
;; Swap C0 and C1 if RP.3 was set
and C0, C1
eor C1, C0
;; Finally, add the power-of-two: A[] += C[]
add A0, C0
adc A1, C1
ret
ENDF __addmask_2
#endif /* L_addmask_2 */
#ifdef L_round_s2
;; R25:R24 = round (R23:R22, R24)
;; Clobbers: R23, R22
DEFUN __roundhq3
subi RP, __HQ_FBIT__ - __HA_FBIT__
ENDF __roundhq3
DEFUN __roundha3
subi RP, __HA_FBIT__ - 1
neg RP
;; [ R25:R24 = 1 << (FBIT-1 - RP)
;; R23:R22 += 1 << (FBIT-1 - RP) ]
XCALL __addmask_2
XJMP __round_s2_const
ENDF __roundha3
#endif /* L_round_s2 */
#ifdef L_round_u2
;; R25:R24 = round (R23:R22, R24)
;; Clobbers: R23, R22
DEFUN __rounduhq3
subi RP, __UHQ_FBIT__ - __UHA_FBIT__
ENDF __rounduhq3
DEFUN __rounduha3
subi RP, __UHA_FBIT__ - 1
neg RP
;; [ R25:R24 = 1 << (FBIT-1 - RP)
;; R23:R22 += 1 << (FBIT-1 - RP) ]
XCALL __addmask_2
XJMP __round_u2_const
ENDF __rounduha3
#endif /* L_round_u2 */
#ifdef L_round_2_const
;; Helpers for 2 byte wide rounding
DEFUN __round_s2_const
brvc 2f
ldi C1, 0x7f
rjmp 1f
;; FALLTHRU (Barrier)
ENDF __round_s2_const
DEFUN __round_u2_const
brcc 2f
ldi C1, 0xff
1:
ldi C0, 0xff
rjmp 9f
2:
;; Saturation is performed now.
;; Currently, we have C[] = 2^{-RP-1}
;; C[] = 2^{-RP}
lsl C0
rol C1
;;
NEG2 C0
;; Clear the bits beyond the rounding point.
and C0, A0
and C1, A1
9: ret
ENDF __round_u2_const
#endif /* L_round_2_const */
#undef A0
#undef A1
#undef C0
#undef C1
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rounding, 4 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#define A0 18
#define A1 A0 + 1
#define A2 A0 + 2
#define A3 A0 + 3
#define C0 22
#define C1 C0 + 1
#define C2 C0 + 2
#define C3 C0 + 3
#ifdef L_addmask_4
;; [ R25:R22 = 1 << (R24 & 31)
;; R21:R18 += 1 << (R24 & 31) ]
;; SREG is set according to the addition
DEFUN __addmask_4
;; R25 = 1 << (R24 & 7)
XCALL __mask1
cpi RP, 1 << 4
sbc C0, C0
sbc C1, C1
;; Swap C2 with C3 if RP.3 is not set
cpi RP, 1 << 3
sbc C2, C2
and C2, C3
eor C3, C2
;; Swap C3:C2 with C1:C0 if RP.4 is not set
and C0, C2 $ eor C2, C0
and C1, C3 $ eor C3, C1
;; Finally, add the power-of-two: A[] += C[]
add A0, C0
adc A1, C1
adc A2, C2
adc A3, C3
ret
ENDF __addmask_4
#endif /* L_addmask_4 */
#ifdef L_round_s4
;; R25:R22 = round (R21:R18, R24)
;; Clobbers: R18...R21
DEFUN __roundsq3
subi RP, __SQ_FBIT__ - __SA_FBIT__
ENDF __roundsq3
DEFUN __roundsa3
subi RP, __SA_FBIT__ - 1
neg RP
;; [ R25:R22 = 1 << (FBIT-1 - RP)
;; R21:R18 += 1 << (FBIT-1 - RP) ]
XCALL __addmask_4
XJMP __round_s4_const
ENDF __roundsa3
#endif /* L_round_s4 */
#ifdef L_round_u4
;; R25:R22 = round (R21:R18, R24)
;; Clobbers: R18...R21
DEFUN __roundusq3
subi RP, __USQ_FBIT__ - __USA_FBIT__
ENDF __roundusq3
DEFUN __roundusa3
subi RP, __USA_FBIT__ - 1
neg RP
;; [ R25:R22 = 1 << (FBIT-1 - RP)
;; R21:R18 += 1 << (FBIT-1 - RP) ]
XCALL __addmask_4
XJMP __round_u4_const
ENDF __roundusa3
#endif /* L_round_u4 */
#ifdef L_round_4_const
;; Helpers for 4 byte wide rounding
DEFUN __round_s4_const
brvc 2f
ldi C3, 0x7f
rjmp 1f
;; FALLTHRU (Barrier)
ENDF __round_s4_const
DEFUN __round_u4_const
brcc 2f
ldi C3, 0xff
1:
ldi C2, 0xff
ldi C1, 0xff
ldi C0, 0xff
rjmp 9f
2:
;; Saturation is performed now.
;; Currently, we have C[] = 2^{-RP-1}
;; C[] = 2^{-RP}
lsl C0
rol C1
rol C2
rol C3
XCALL __negsi2
;; Clear the bits beyond the rounding point.
and C0, A0
and C1, A1
and C2, A2
and C3, A3
9: ret
ENDF __round_u4_const
#endif /* L_round_4_const */
#undef A0
#undef A1
#undef A2
#undef A3
#undef C0
#undef C1
#undef C2
#undef C3
#undef RP
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rounding, 8 Bytes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#define RP 16
#define FBITm1 31
#define C0 18
#define C1 C0 + 1
#define C2 C0 + 2
#define C3 C0 + 3
#define C4 C0 + 4
#define C5 C0 + 5
#define C6 C0 + 6
#define C7 C0 + 7
#define A0 16
#define A1 17
#define A2 26
#define A3 27
#define A4 28
#define A5 29
#define A6 30
#define A7 31
#ifdef L_rounddq3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __rounddq3
ldi FBITm1, __DQ_FBIT__ - 1
clt
XJMP __round_x8
ENDF __rounddq3
#endif /* L_rounddq3 */
#ifdef L_roundudq3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __roundudq3
ldi FBITm1, __UDQ_FBIT__ - 1
set
XJMP __round_x8
ENDF __roundudq3
#endif /* L_roundudq3 */
#ifdef L_roundda3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __roundda3
ldi FBITm1, __DA_FBIT__ - 1
clt
XJMP __round_x8
ENDF __roundda3
#endif /* L_roundda3 */
#ifdef L_rounduda3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __rounduda3
ldi FBITm1, __UDA_FBIT__ - 1
set
XJMP __round_x8
ENDF __rounduda3
#endif /* L_rounduda3 */
#ifdef L_roundta3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __roundta3
ldi FBITm1, __TA_FBIT__ - 1
clt
XJMP __round_x8
ENDF __roundta3
#endif /* L_roundta3 */
#ifdef L_rounduta3
;; R25:R18 = round (R25:R18, R16)
;; Clobbers: ABI
DEFUN __rounduta3
ldi FBITm1, __UTA_FBIT__ - 1
set
XJMP __round_x8
ENDF __rounduta3
#endif /* L_rounduta3 */
#ifdef L_round_x8
DEFUN __round_x8
push r16
push r17
push r28
push r29
;; Compute log2 of addend from rounding point
sub RP, FBITm1
neg RP
;; Move input to work register A[]
push C0
mov A1, C1
wmov A2, C2
wmov A4, C4
wmov A6, C6
;; C[] = 1 << (FBIT-1 - RP)
XCALL __clr_8
inc C0
XCALL __ashldi3
pop A0
;; A[] += C[]
add A0, C0
adc A1, C1
adc A2, C2
adc A3, C3
adc A4, C4
adc A5, C5
adc A6, C6
adc A7, C7
brts 1f
;; Signed
brvc 3f
;; Signed overflow: A[] = 0x7f...
brvs 2f
1: ;; Unsigned
brcc 3f
;; Unsigned overflow: A[] = 0xff...
2: ldi C7, 0xff
ldi C6, 0xff
wmov C0, C6
wmov C2, C6
wmov C4, C6
bld C7, 7
rjmp 9f
3:
;; C[] = -C[] - C[]
push A0
ldi r16, 1
XCALL __ashldi3
pop A0
XCALL __negdi2
;; Clear the bits beyond the rounding point.
and C0, A0
and C1, A1
and C2, A2
and C3, A3
and C4, A4
and C5, A5
and C6, A6
and C7, A7
9: ;; Epilogue
pop r29
pop r28
pop r17
pop r16
ret
ENDF __round_x8
#endif /* L_round_x8 */
#undef A0
#undef A1
#undef A2
#undef A3
#undef A4
#undef A5
#undef A6
#undef A7
#undef C0
#undef C1
#undef C2
#undef C3
#undef C4
#undef C5
#undef C6
#undef C7
#undef RP
#undef FBITm1
;; Supply implementations / symbols for the bit-banging functions
;; __builtin_avr_bitsfx and __builtin_avr_fxbits
#ifdef L_ret
DEFUN __ret
ret
ENDF __ret
#endif /* L_ret */
Reference in New Issue Copy Permalink